[Quantity-frequency scale (QF Scale) for adolescent problem drinking].
From 1990 to 1992, we surveyed 14,438 Japanese high school students from nine prefectures on drinking behavior. Based on this survey, we developed a new Quantity-Frequency Scale (QF Scale) for adolescent problem drinking. Each adolescent is scored from 0 to 6 by the QF Scale, which is composed of scores of drinking quantities and frequencies. Adolescents were assessed as normal adolescent, drinkers and problem drinkers by QF Scale scores. The normal adolescent (score 0) categorized by the QF Scale drinks none or little and obeys the Law Prohibiting Adolescents from Drinking. The drinker (score 1-3) categorized by the QF Scale drinks at least several times a year, but drinks little each time. The problem drinker (score 4-6) categorized by the QF Scale drinks several times a week and has at least two drink (1 drink is equivalent to a glass of beer) each time, once a week with at least 3 drinks, or once or twice a month with at least 6 drinks each time. The problem drinkers show a physical, psychological and social high risk for alcohol. The validity of the QF Scale was examined. The results showed that the problem drinkers had significantly frequent blackout, significantly frequent drinking when they had emotional conflicts or they were alone, and drank significantly more hard liquor than the drinkers and normal adolescents. Among the high school students surveyed, 39.5% were normal adolescents, 43.2% were drinkers and 17.4% were problem drinkers. In conclusion, the QF Scale is a useful instrument for assessment of adolescent problem drinking.